• 【连续左旋肉碱生产过程中转基因大肠杆菌菌株的质粒维持和生理学。】 复制标题 收藏 收藏
    DOI:10.1007/s10529-007-9432-4 复制DOI
    作者列表:Bernal V,González-Veracruz M,Cánovas M,Iborra JL
    BACKGROUND & AIMS: :The effect of immobilization on cell physiology and how this determines cell metabolic performance is an important concern for developing bioprocess. This is particularly true for genetically modified microorganisms and their genetic stability. For this reason the stability and physiological state of plasmid-bearing E. coli cells were ascertained by flow cytometry. Differences in the cellular DNA and protein content (15-20%) permit discrimination of control and plasmid-bearing cells, as well as adaptation to continuous cultivation conditions in both freely suspended and immobilized states to be monitored. Moreover, the observed metabolic burden due to maintenance and over-expression of plasmid-coded genetic material and slow cell growth in poorly-viable immobilized cells were found to be the main factors contributing to strain stabilization.
    背景与目标: :固定化对细胞生理的影响以及如何决定细胞代谢性能是发展生物过程的重要考虑因素。对于转基因微生物及其遗传稳定性尤其如此。因此,通过流式细胞术确定了带有质粒的大肠杆菌细胞的稳定性和生理状态。细胞DNA和蛋白质含量的差异(15-20%)可以区分对照细胞和带有质粒的细胞,并可以监测自由悬浮和固定状态下连续培养条件的适应性。此外,已发现由于质粒编码的遗传物质的维持和过表达以及在存活率低的固定化细胞中缓慢的细胞生长而导致的观察到的代谢负担是促成菌株稳定的主要因素。
  • 【大麦(Hordeum vulgar L.)抗寒成分的遗传分析。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Karsai I,Mészáros K,Bedó Z,Hayes PM,Pan A,Chen F
    BACKGROUND & AIMS: Winterhardiness in cereals is the consequence of a number of complex and interacting componentscold tolerance, vernalization requirement and photoperiod sensitivity. An understanding of the genetic basis of these component traits should allow for more effective selection. Genome map-based analyses hold considerable promise for dissecting complex phenotypes. A 74-point linkage map was developed from one hundred double haploid lines derived from a winter x spring barley cross and used as the basis for quantitative trait locus (QTL) analyses to determine the chromosome location of genes controlling components of winterhardiness. Despite the greater genome coverage provided by the current map, a previously-reported interval on chromosome 7 remains the only region where significant QTL effects for winter survival were detected in this population. QTLs for heading date under 24 h light map to the same region. A QTL for heading date under this photoperiod regime also maps to chromosome 2. A distinct set of QTLs mapping to chromosomes 1, 2, 3 and 5 determined heading date under 8 h light. Patterns of differential QTL expression underscore the complexity of Winterhardiness.

    背景与目标: 谷物的耐寒性是许多复杂且相互作用的成分的结果,包括耐寒性,春化要求和光周期敏感性。对这些成分性状的遗传基础的了解应有助于更有效的选择。基于基因组图谱的分析在解剖复杂表型方面具有广阔的前景。用一百个来自冬季x春季大麦杂交的双单倍体系构建了74点连锁图谱,并将其用作定量性状基因座(QTL)分析的基础,以确定控制耐寒性成分的基因的染色体位置。尽管当前图谱提供了更大的基因组覆盖范围,但先前在7号染色体上报告的间隔仍然是在该种群中检测到对冬季存活具有显着QTL影响的唯一区域。在24小时光照下朝向日期的QTL映射到同一区域。在此光周期条件下,抽穗期的QTL也映射到染色体2。在8 h光照下,映射到染色体1、2、3和5的一组独特的QTL确定了抽穗期。 QTL差异表达模式强调了耐寒性的复杂性。

  • 【番木瓜脂肪酶间歇性开放反应模式生物合成(S)-萘普生淀粉酯。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Wang Y,Xin JY,Li QH,Sun LR,Xia CG
    BACKGROUND & AIMS: :Inorder to brought S-naproxen into small intestine, an optically pure (S)-naproxen starch ester was produced by lipase through enantio-selective trans-esterification of racemic naproxen methyl ester with pretreatment starch in solvent system. With carefully selection of the reaction medium (isooctane), lipase (Carica Papaya Lipase, CPL) and the reaction mode (intermittent opening), a high conversion rate (48.6%) and enantiomeric excess of product (99.6%) was obtained. The slow release macromolecular (S)-Naproxen had been synthesized to improve the efficacy of racemic naproxen and overcome its side effects. The enanitomeric ratio of CPL (E=52.5) was higher than CRL (E=22) and greatly influenced by the byproduct methyl alcohol. The intermittent opening reaction mode was the effective way to remove the inhibition of methyl alcohol and to improve the enantio-selectivity of CPL. S-naproxen starch was confirmed by HPLC and 1H NMR. This method may also apply to preparation the other optically pure 2-phenylpropionic acid derivatives. S-naproxen starch was a new optically pure derivatives possessing emulsifying and slow release properties would be widely applied to the food, pharmaceutical and biomedical industries.
    背景与目标: :为了使S-萘普生进入小肠,在溶剂体系中,脂肪酶通过外消旋萘普生甲酯与淀粉的预处理将外消旋萘普生甲酯进行对映选择性酯交换反应,制得了光学纯的(S)-萘普生淀粉酯。通过仔细选择反应介质(异辛烷),脂肪酶(番木瓜脂肪酶,CPL)和反应模式(间歇打开),可获得高转化率(48.6%)和对映体过量的产物(99.6%)。已经合成了缓释大分子(S)-萘普生,以提高外消旋萘普生的功效并克服其副作用。 CPL(E = 52.5)的对映体比率高于CRL(E = 22),并受到副产物甲醇的很大影响。间歇性开放反应模式是消除甲醇抑制作用,提高CPL对映选择性的有效途径。 S-萘普生淀粉通过HPLC和1H NMR确认。该方法还可以用于制备其他光学纯的2-苯基丙酸衍生物。 S-萘普生淀粉是一种具有乳化和缓释性能的新型光学纯衍生物,将被广泛应用于食品,制药和生物医学行业。
  • 【茄茄花药培养中的愈伤组织形成和器官发生。】 复制标题 收藏 收藏
    DOI:10.1016/S0176-1617(84)80029-2 复制DOI
    作者列表:Reynolds TL
    BACKGROUND & AIMS: :In anther cultures of Solanum carolinense L., Murashige and Skoog's medium (MS) supplemented with 2.2 mg · l(-1) 2,4-dichlorophenoxyacetic acid (2,4-D) and 6.0 mg · l(-1) kinetin (KIN) served as callus induction medium. Cytological observations confirmed that the callus originated from pollen grains. Upon transfer to medium lacking 2,4-D, callus cultures regenerated shoots exclusively. However, maximum efficiency in regeneration occurred only after callus had been maintained in the presence of 2,4-D for a minimum of 12 weeks. Callus younger than this or older than 16 weeks showed a significant decline in organogenic competence when transferred to the appropriate medium. It is suggested that 2,4-D may establish a transitory potential for regeneration in pollen-derived callus cultures but must be removed before this potential can be expressed.
    背景与目标: :在茄茄的花药培养中,Murashige和Skoog培养基(MS)补充了2.2 mg·l(-1)2,4-二氯苯氧基乙酸(2,4-D)和6.0 mg·l(-1)激动素(KIN)用作愈伤组织诱导培养基。细胞学观察证实愈伤组织起源于花粉粒。转移到缺乏2,4-D的培养基后,愈伤组织培养物专门再生芽。但是,只有在2,4-D存在下保持愈伤组织至少12周之后,再生的最大效率才会出现。小于此年龄或大于16周的愈伤组织转移到适当的培养基中后,其器官发生能力显着下降。建议2,4-D可能在花粉衍生的愈伤组织培养中建立一个短暂的再生潜能,但在表达该潜能之前必须将其除去。
  • 【银杏叶和牛痘越桔的提取物可防止低密度脂蛋白胆固醇的光诱导氧化。】 复制标题 收藏 收藏
    DOI:10.1016/S0944-7113(97)80006-2 复制DOI
    作者列表:Rasetti MF,Caruso D,Galli G,Bosisio E
    BACKGROUND & AIMS: :Oxidation of low density lipoproteins (LDL) favours cholesterol loading in macrophages and formation of "foam cells", typical of the early atheroma lesions. LDL cholesterol oxidation generates oxysterols, extremely cytotoxic molecular species with diverse biological activities. Vegetable polyphenols are dietary components of pharmacological interest for their anti-oxidant properties. Ginkgo biloba L. (Gingkoaceae) leaves and Vaccinium myrtillus L. (Ericaceae) fruits are known for their beneficial effects in the treatment of various diseases involving free radicals and oxidative damage to biological lipids. In this study we investigated the effect of Ginkgo biloba L. and Vaccinium myrtillus L. extracts on the formation of cholesterol oxides during the photo induced oxidation of human LDL. The results demonstrate a concentration dependent inhibition of oxysterol formation in the presence of both extracts. Protection against oxidation was confirmed by the partial restoration of the normal electrophoretic mobility of LDL, which has been influenced by the UV irradiation. These effects extend knowledge of the therapeutic action of Ginkgo biloba L. and Vaccinium myrtillus L. as agents in anti-atherosclerotic regimens.
    背景与目标: 低密度脂蛋白(LDL)的氧化有助于巨噬细胞中的胆固醇负载和形成“泡沫细胞”,这是早期动脉粥样硬化病变的典型表现。 LDL胆固醇的氧化产生氧固醇,这是具有多种生物活性的极具细胞毒性的分子物种。植物多酚因其抗氧化性能而成为具有药理学意义的饮食成分。银杏叶(Gingkoaceae)叶和牛痘越橘(Ericaceae)水果因其在治疗多种疾病中的有益作用而广为人知,这些疾病涉及自由基和对生物脂质的氧化损伤。在这项研究中,我们研究了银杏叶提取物和牛痘越桔提取物在光诱导人LDL氧化过程中对胆固醇氧化物形成的影响。结果表明在两种提取物存在下,浓度依赖性抑制氧固醇的形成。 LDL的正常电泳迁移率已部分恢复,这证实了抗氧化的作用,该迁移率已受到紫外线辐射的影响。这些作用扩展了银杏叶和越桔越桔作为抗动脉粥样硬化治疗剂的治疗作用的知识。
  • 【贝叶斯网络说明了玉米(Zea mays L.)中的基因组和残留性状联系。】 复制标题 收藏 收藏
    DOI:10.1534/g3.117.044263 复制DOI
    作者列表:Töpner K,Rosa GJM,Gianola D,Schön CC
    BACKGROUND & AIMS: :Relationships among traits were investigated on the genomic and residual levels using novel methodology. This included inference on these relationships via Bayesian networks and an assessment of the networks with structural equation models. The methodology employed three steps. First, a Bayesian multiple-trait Gaussian model was fitted to the data to decompose phenotypic values into their genomic and residual components. Second, genomic and residual network structures among traits were learned from estimates of these two components. Network learning was performed using six different algorithmic settings for comparison, of which two were score-based and four were constraint-based approaches. Third, structural equation model analyses ranked the networks in terms of goodness of fit and predictive ability, and compared them with the standard multiple-trait fully recursive network. The methodology was applied to experimental data representing the European heterotic maize pools Dent and Flint (Zea mays L.). Inferences on genomic and residual trait connections were depicted separately as directed acyclic graphs. These graphs provide information beyond mere pairwise genetic or residual associations between traits, illustrating for example conditional independencies and hinting at potential causal links among traits. Network analysis suggested some genetic correlations as potentially spurious. Genomic and residual networks were compared between Dent and Flint.
    背景与目标: :使用新颖的方法,在基因组和残基水平上研究了性状之间的关系。这包括通过贝叶斯网络推断这些关系,以及使用结构方程模型评估网络。该方法采用三个步骤。首先,将贝叶斯多特征高斯模型拟合到数据中,以将表型值分解为它们的基因组和残差成分。其次,从这两个组成部分的估计中了解了性状之间的基因组和残留网络结构。使用六种不同的算法设置进行网络学习进行比较,其中两种基于得分,四种基于约束。第三,结构方程模型分析根据拟合优度和预测能力对网络进行排名,并将其与标准的多特征完全递归网络进行比较。将该方法应用于代表欧洲杂种玉米库Dent和Flint(Zea mays L.)的实验数据。关于基因组和残留性状联系的推论分别被描述为有向无环图。这些图提供了性状之间仅成对的遗传或残差关联之外的信息,举例说明了条件独立性,并暗示了性状之间的潜在因果关系。网络分析表明某些遗传相关性可能是虚假的。比较了Dent和Flint之间的基因组网络和残差网络。
  • 【多年生黑麦草(Lolium perenne L.)编码果糖:果糖6G-果糖基转移酶(6G-FFT)/果糖:果糖1-果糖基转移酶(1-FFT)的cDNA的分子和功能表征。】 复制标题 收藏 收藏
    DOI:10.1093/jxb/erl034 复制DOI
    作者列表:Lasseur B,Lothier J,Djoumad A,De Coninck B,Smeekens S,Van Laere A,Morvan-Bertrand A,Van den Ende W,Prud'homme MP
    BACKGROUND & AIMS: :Fructans are the main storage compound in Lolium perenne. To account for the prevailing neokestose-based fructan synthesis in this species, a cDNA library of L. perenne was screened by using the onion (Allium cepa) fructan:fructan 6G-fructosyltransferase (6G-FFT) as a probe. A full length Lp6G-FFT clone was isolated with significant homologies to vacuolar type fructosyltransferases and invertases. The functionality of the cDNA was tested by heterologous expression in Pichia pastoris. The recombinant protein demonstrated both 6G-FFT and fructan:fructan 1-fructosyltransferase activities (1-FFT) with a maximum 6G-FFT/1-FFT ratio of two. The activity of 6G-FFT was investigated with respect to developmental stage, tissue distribution, and alterations in carbohydrate status expression and compared to sucrose:sucrose 1-fructosyltransferase (1-SST). Lp6G-FFT and Lp1-SST were predominantly expressed in the basal part of elongating leaves and leaf sheaths. Expression of both genes declined along the leaf axis, in parallel with the spatial occurrence of fructan and fructosyltransferase activities. Surprisingly, Lp6G-FFT was highly expressed in photosynthetically active tissues where very low extractable fructosyltransferase activity and fructan amounts were detected, suggesting a post-transcriptional regulation of expression. Lp6G-FFT gene expression increased only in elongating leaves following similar increases of sucrose content in blades, sheaths, and elongating leaf bases. Regulation of Lp6G-FFT gene expression depends on the tissue according to its sink-source status.
    背景与目标: :果聚糖是黑麦草的主要贮藏化合物。为了说明该物种中普遍存在的基于新核糖的果聚糖合成,使用洋葱(葱属)果聚糖:果聚糖6G-果糖基转移酶(6G-FFT)作为探针筛选了紫苏乳酸杆菌的cDNA文库。分离出全长Lp6G-FFT克隆,与液泡型果糖基转移酶和转化酶具有显着同源性。通过在毕赤酵母中的异源表达来测试cDNA的功能。重组蛋白同时具有6G-FFT和果聚糖:果聚糖1-果糖基转移酶活性(1-FFT),最大6G-FFT / 1-FFT比率为2。研究了6G-FFT的活性,涉及发育阶段,组织分布和碳水化合物状态表达的变化,并与蔗糖:蔗糖1-果糖基转移酶(1-SST)进行了比较。 Lp6G-FFT和Lp1-SST主要在伸长的叶和叶鞘的基部表达。两种基因的表达沿叶轴下降,与果聚糖和果糖基转移酶活性的空间发生平行。出人意料的是,Lp6G-FFT在光合作用活跃的组织中高表达,在该组织中检测到极低的果糖基转移酶活性和果聚糖含量,表明转录后的表达调控。 Lp6G-FFT基因表达仅在叶片,鞘和叶片基部中蔗糖含量的相似增加之后才在叶片中增加。 Lp6G-FFT基因表达的调节取决于组织的汇源状态。
  • 【鳟鱼神经系统的胚胎发育过程中同源异型盒衔接基因的表达。】 复制标题 收藏 收藏
    DOI:10.1016/0304-3940(91)90488-f 复制DOI
    作者列表:Vecino E,Ekström P
    BACKGROUND & AIMS: :The expression of the engrailed homeobox gene during trout embryogenesis has been examined using immunohistochemistry and the monoclonal antibody 'Mab 4D9'. Engrailed has been suggested to play an important role during development by controlling position-specific characteristics in the CNS of the early embryo. In the present study we have analyzed the expression of engrailed at 5 stages of embryonic development of the trout (Salmo fario L.). The earliest stage analyzed was when the optic vesicles appear. Engrailed was then expressed in the posterior mesencephalon and anterior metencephalon, in a caudorostrally decreasing gradient. As the embryo develops, the pattern of the engrailed expression increases in spatial complexity. Thus, in the later stages of development, just before hatching, engrailed was found in hypothalamic areas, the germinative matrix layer of the cerebellum, the mesencephalic tegmentum, the caudal optic tectum and in the area of the trigeminal motor nucleus. This is similar to the distribution of engrailed in embryos of amphibians, birds and mammals.
    背景与目标: :已经使用免疫组织化学和单克隆抗体“ Mab 4D9”检查了鳟鱼胚胎发生过程中同源异型盒基因的表达。有人认为,Engrailed通过控制早期胚胎中枢神经系统中特定于位置的特征,在发育过程中起重要作用。在本研究中,我们已经分析了鳟鱼胚胎发育的5个阶段参与的表达(Salmo fario L.)。分析的最早阶段是何时出现囊泡。然后,在前中脑后部和前中脑中,以caorrostrally递减的梯度表达“ g满志”。随着胚胎的发育,外向表达的模式在空间复杂性上增加。因此,在发育的后期,即在孵化之前,在下丘脑区域,小脑的发芽基质层,中脑被膜,尾端视神经顶盖和三叉神经运动核区域内发现了变位。这类似于两栖动物,鸟类和哺乳动物的胚胎中的虫分布。
  • 【腰部肌肉组织对L 4L 5椎间盘的前向剪切力的降低。】 复制标题 收藏 收藏
    DOI:10.1016/0268-0033(91)90005-B 复制DOI
    作者列表:Potvin JR,Norman RW,McGill SM
    BACKGROUND & AIMS: :The purpose of this study was to assess the possible role of muscles in offsetting the anterior shear forces caused by the load and upper body mass and their accelerations that act on the L 4L 5, intervertebral joint during dynamic squat lifts. Fifteen males lifted five loads from 5.8 to 32.4 kg. Anterior shear forces estimated to be acting on the lumber spine, based on model output, ranged from 492 N at 5.8 kg to 736 N at 32.4 kg. However, the peak shear force that had to be supported by the facets and possibly the disc remained relatively constant at approximately 200 N, regardless of the load mass. The posteriorly directed fascicles of the lumbar portions of the iliocostalis lumborum and longissimus thoracis muscles increased their force output, as estimated from an EMG driven model, in proportion to the anterior load shear force demands, thereby sharing the load on the intervertebral joint. It appears that the combination of anatomical design and neural control of the musculature leads to a situation where the resultant shear force on the joint can be maintained at a relatively constant and safe level in the types of lifts studied. This 'safety' mechanism is useful only with the preservation of lordosis during lifting, when the muscles must provide the majority of the support moment.
    背景与目标: :这项研究的目的是评估在动态下蹲举升过程中,肌肉在抵消由负荷和上半身及其在L 4L 5椎间关节上作用的加速度所引起的前剪切力中的可能作用。 15头雄性将五种负载从5.8公斤提升至32.4公斤。根据模型输出,估计作用在木材脊柱上的前剪力范围从5.8 kg的492 N到32.4 kg的736N。然而,无论负载质量如何,必须由刻面支撑并可能由圆盘支撑的峰值剪切力保持相对恒定,约为200N。根据肌电图驱动模型估计,the肌和腰最长肌的腰部向后束束的力量输出与前部剪切力需求成正比,从而分担了椎间关节的负荷。看起来,肌肉组织的解剖学设计和神经控制的结合导致了这样一种情况,在所研究的举重类型中,在关节上产生的剪切力可以保持在相对恒定和安全的水平。这种“安全”机制仅在举重过程中保留脊柱前凸肌时有用,此时肌肉必须提供大部分的支撑力矩。
  • 【通过45S rDNA的FISH区分雌雄异株菠菜(菠菜)的性染色体。】 复制标题 收藏 收藏
    DOI:10.1159/000093335 复制DOI
    作者列表:Lan T,Zhang S,Liu B,Li X,Chen R,Song W
    BACKGROUND & AIMS: :Spinacia oleracea L. (spinach) is a dioecious species with both male and female plants having 2n = 2x = 12 chromosomes, consisting of two large metacentrics, two long subtelocentrics, two short subtelocentrics, two acrocentrics, and four submetacentrics. The location of 45S rDNA was investigated on metaphase chromosomes using fluorescence in situ hybridization (FISH). The numbers of 45S rDNA foci in diploid sets of chromosomes from females was six and from males was five. All the fluorescent foci lay in secondary constrictions and the satellites. Our results indicate that an XY-type sex chromosome system could be present in spinach where the Y chromosome lacks a 45S RNA focus.
    背景与目标: 菠菜(Spinacia oleracea L.)(菠菜)是雌雄异体的物种,其雄性和雌性植物均具有2n = 2x = 12条染色体,由两个大的亚中心,两个长的亚中心,两个短的亚中心,两个顶心和四个亚中心组成。使用荧光原位杂交(FISH)研究了45S rDNA在中期染色体上的位置。来自雌性的二倍体染色体组中的45S rDNA焦点数目为六个,来自雄性的数目为45个。所有的荧光灶都位于次要收缩区和人造卫星中。我们的结果表明,XY染色体缺乏45S RNA焦点的菠菜中可能存在XY型性染色体系统。
  • 【分泌胰岛素的L细胞用于治疗胰岛素依赖型糖尿病。】 复制标题 收藏 收藏
    DOI:10.1016/j.bbrc.2008.03.154 复制DOI
    作者列表:Bara H,Sambanis A
    BACKGROUND & AIMS: :Cell-based treatments for insulin-dependent diabetes (IDD) may provide more physiologic regulation of blood glucose levels than daily insulin injections, thereby reducing the occurrence of secondary complications associated with diabetes. An autologous cell source is especially attractive for regulatory and ethical reasons in addition to eliminating the need for immunosuppression. This study uses non-beta-cells, genetically modified for physiologic insulin secretion. Enteroendocrine L-cells, exhibit regulated secretion in response to physiologic stimuli and their endogenous products are fully compatible with prandial metabolism. Murine GLUTag L-cells were transfected with a plasmid co-expressing human insulin and neomycin resistance and the stable cell line, GLUTag-INS, was established. Secretion properties of GLUTag-INS cells were investigated in vitro through induced secretion tests using meat hydrolysate or 3-isobutyl-1-methylxanthine and forskolin as secretagogues. GLUTag-INS cells rapidly co-secreted recombinant insulin and endogenous glucagon-like peptide in response to metabolic cues from the surrounding medium and demonstrated efficient processing of proinsulin to insulin.
    背景与目标: :基于细胞的胰岛素依赖型糖尿病(IDD)治疗可能比每天注射胰岛素提供更多的生理血糖水平调节,从而减少与糖尿病相关的继发性并发症的发生。除了消除免疫抑制的需要外,出于调节和伦理原因,自体细胞来源也是特别有吸引力的。这项研究使用了经过基因修饰的非β细胞,用于生理性胰岛素分泌。肠内分泌L细胞在生理刺激下表现出受调节的分泌,其内源性产物与膳食代谢完全相容。用共表达人胰岛素和新霉素抗性的质粒转染鼠GLUTag L细胞,并建立稳定的细胞系GLUTag-INS。使用肉水解产物或3-异丁基-1-甲基黄嘌呤和毛喉素作为促分泌素,通过诱导分泌试验体外研究了GLUTag-INS细胞的分泌特性。 GLUTag-INS细胞响应周围环境中的代谢信号而迅速共分泌重组胰岛素和内源性胰高血糖素样肽,并证明胰岛素原有效转化为胰岛素。
  • 【赤霉素与小麦株高杂种优势(Triticum aestivum L.)。】 复制标题 收藏 收藏
    DOI:10.1186/1471-2156-8-40 复制DOI
    作者列表:Zhang Y,Ni Z,Yao Y,Nie X,Sun Q
    BACKGROUND & AIMS: BACKGROUND:Heterosis in internode elongation and plant height are commonly observed in hybrid plants, and higher GAs contents were found to be correlated with the heterosis in plant height. However, the molecular basis for the increased internode elongation in hybrids is unknown. RESULTS:In this study, heterosis in plant height was determined in two wheat hybrids, and it was found that the increased elongation of the uppermost internode contributed mostly to the heterosis in plant height. Higher GA4 level was also observed in a wheat hybrid. By using the uppermost internode tissues of wheat, we examined expression patterns of genes participating in both GA biosynthesis and GA response pathways between a hybrid and its parental inbreds. Our results indicated that among the 18 genes analyzed, genes encoding enzymes that promote synthesis of bioactive GAs, and genes that act as positive components in the GA response pathways were up-regulated in hybrid, whereas genes encoding enzymes that deactivate bioactive GAs, and genes that act as negative components of GA response pathways were down-regulated in hybrid. Moreover, the putative wheat GA receptor gene TaGID1, and two GA responsive genes participating in internode elongation, GIP and XET, were also up-regulated in hybrid. A model for GA and heterosis in wheat plant height was proposed. CONCLUSION:Our results provided molecular evidences not only for the higher GA levels and more active GA biosynthesis in hybrid, but also for the heterosis in plant height of wheat and possibly other cereal crops.
    背景与目标: 背景:杂种植物通常观察到节间伸长和株高的杂种优势,并且较高的GA含量与株高的杂种优势相关。但是,尚不清楚杂种中节间伸长增加的分子基础。
    结果:本研究确定了两个小麦杂种的株高杂种优势,发现最上节间的伸长率增加主要是造成株高杂种优势的原因。在小麦杂种中也观察到较高的GA4水平。通过使用小麦的最上节间组织,我们检查了参与杂种及其亲本近交种之间GA生物合成和GA响应途径的基因的表达模式。我们的结果表明,在所分析的18个基因中,编码促进生物活性GA合成的酶的基因和在GA反应途径中充当正向成分的基因在杂种中上调,而编码使生物活性GA失活的酶的基因和基因杂种中GA反应途径的负性成分被下调。此外,杂种小麦中的假定小麦GA受体基因TaGID1和两个参与节间延长的GA响应基因GIP和XET也被上调。提出了遗传算法和小麦株高杂种优势模型。
    结论:我们的结果不仅为杂种中较高的GA水平和更活跃的GA生物合成提供了分子证据,还为小麦和可能的其他谷物作物的株高杂种优势提供了分子证据。
  • 【肉食蟹肉(Sartophaga carnaria L。)(双翅目:Sarcophagidae)所有阶段的脂肪酸的抗真菌活性。】 复制标题 收藏 收藏
    DOI:10.1016/j.micres.2013.07.011 复制DOI
    作者列表:Gołębiowski M,Urbanek A,Oleszczak A,Dawgul M,Kamysz W,Boguś MI,Stepnowski P
    BACKGROUND & AIMS: :Fatty acids as components of cuticular lipids of insects play a significant role in antifungal in protection against fungal infection. The chemical composition of cuticular and internal extracts obtained from all developmental stages of flesh flies Sarcophaga carnaria was identified. The fatty acids were detected using gas chromatography coupled with mass spectrometry and the most abundant for all examined stages were: 18:1 > 16:0 > 16:1 > 18:0 > 18:2. Polyunsaturated fatty acids (PUFA) C20 were found in both, cuticular and internal extracts. GC-MS analysis showed higher relative content of PUFA in adults than in preimaginal stages. Fatty acids alone as well as their cuticular and internal extracts obtained from larvae, pupae male and female of S. carnaria were tested according to their potential antimicrobial activity against entomopathogenic fungi: Paecilomyces lilacinus, Paecilomyces fumosoroseus, Lecanicillium lecanii, Metarhizium anisopliae, Beauveria bassiana (Tve-N39) and B. bassiana (Dv-1/07). FA presented diverse antimicrobial activity depending on the length of the chain and the presence of unsaturated bonds. Short chain and unsaturated FA (6:0, 11:0, 13:0) have shown significantly stronger activity against fungi but they were detected in lower concentrations. PUFA inhibit fungal growth more effectively than unsaturated long chain fatty acids. Cuticular and internal extracts of all living forms of S. carnaria exhibited approximately equal activity against tested entomopathogenic fungi. We presumed that the most abundant saturated long chain FA and additionally PUFA founded in our analysis are involved in protecting the flies against fungal infection.
    背景与目标: :脂肪酸作为昆虫表皮脂质的成分,在抗真菌保护真菌感染中起着重要作用。确定了从果蝇Sarcophaga carnaria的所有发育阶段获得的表皮和内部提取物的化学成分。使用气相色谱和质谱法检测脂肪酸,所有检查阶段中最丰富的脂肪酸为:18:1> 16:0> 16:1> 18:0> 18:2。在表皮和内部提取物中均发现了多不饱和脂肪酸(PUFA)C20。 GC-MS分析显示,成年人中PUFA的相对含量高于想象前阶段。根据脂肪酸对昆虫病原真菌的潜在抗微生物活性,对脂肪酸以及从幼虫,p男性和女性of的p和表皮和内部提取物进行了测试:淡紫色拟青霉,烟酸拟青霉,Lecanicillium lecanii,南美白僵菌,Beauverhizium anisopliae(博韦Tve-N39)和球孢白僵菌(Dv-1 / 07)。根据链的长度和不饱和键的存在,FA表现出多种抗菌活性。短链和不饱和脂肪酸(6:0,11:0,13:0)已显示出明显较强的抗真菌活性,但在较低浓度下被检测到。 PUFA比不饱和长链脂肪酸更有效地抑制真菌生长。沙门氏菌所有生活形式的表皮和内部提取物对被测昆虫病原真菌表现出大致相同的活性。我们推测,在我们的分析中建立的最丰富的饱和长链FA和另外的PUFA可以保护果蝇免受真菌感染。
  • 【同步过程和分离过程的比较:捕获作物和水生植物生物量的糖化和嗜热L-乳酸发酵。】 复制标题 收藏 收藏
    DOI:10.1080/09593330.2012.669412 复制DOI
    作者列表:Akao S,Maeda K,Nakatani S,Hosoi Y,Nagare H,Maeda M,Fujiwara T
    BACKGROUND & AIMS: :Catch crop candidates (corn, guinea grass) for recovering nutrients from farm soil and aquatic plants (water caltrop, water hyacinth) were utilized to produce L-lactic acid. The efficiencies ofpre-treatment methods for enzymatic saccharification and L-lactate production of two fermentation processes, thermophilic simultaneous saccharification and fermentation (SSF), as well as separate saccharification and fermentation, were compared. Conditions were set at 55 degrees C and pH 5.5 for non-sterile fermentation. Alkaline/peroxide pre-treatment proved the most effective for saccharification in pre-treated corn, guinea grass, water caltrop and water hyacinth with glucose yields of 0.23, 0.20, 0.11 and 0.14 g/g-dry native biomass (24-hour incubation period), respectively. Examination of the two types of thermophilic L-lactate fermentation employed following alkaline/peroxide pre-treatment and saccharification demonstrated that the L-lactate yield obtained using SSF (0.15 g/g in the case of corn) was lower than that obtained using separate saccharification and fermentation (0.28 g/g in the case of corn). The lower yield obtained from SSF is likely to have resulted from the saccharification conditions used in the present study, as the possibility of cellulase deactivation during SSF by thermophilic L-lactate producing bacteria existed. A cellulase that retains high activity levels under non-sterile conditions and a L-lactate producer without cellulose hydrolysis activity would be required in order for SSF to serve as an effective method of L-lactate production.
    背景与目标: :利用候选农作物(玉米,几内亚草)从农场土壤和水生植物(菱角,水葫芦)中回收营养,以生产L-乳酸。比较了酶促糖化和L-乳酸生产两个发酵过程的方法的效率,即高温同时糖化和发酵(SSF),以及单独的糖化和发酵。非无菌发酵的条件设定在55摄氏度和pH 5.5。碱性/过氧化物预处理被证明对预处理的玉米,豚鼠草,菱角和水葫芦最有效的糖化作用,其葡萄糖产量分别为干自然生物量0.23、0.20、0.11和0.14 g / g(24小时培养期) ), 分别。对碱/过氧化物预处理和糖化后使用的两种嗜热L-乳酸发酵进行的检查表明,使用SSF获得的L-乳酸产量(对于玉米为0.15 g / g)低于使用单独糖化获得的L-乳酸产量和发酵(对于玉米为0.28 g / g)。由于存在嗜热L-乳酸的细菌在SSF中纤维素酶失活的可能性,本研究中使用的糖化条件可能导致SSF的收率降低。为了使SSF成为生产L-乳酸的有效方法,将需要在非无菌条件下保持高活性水平的纤维素酶和没有纤维素水解活性的L-乳酸生产者。
  • 【可可豆(如可可和巧克力)产品中存在的四氢异喹啉Salsolinol的体外药理活性。】 复制标题 收藏 收藏
    DOI:10.1016/s0378-8741(00)00291-9 复制DOI
    作者列表:Melzig MF,Putscher I,Henklein P,Haber H
    BACKGROUND & AIMS: :Cocoa and chocolate contain the tetrahydroisoquinoline alkaloid salsolinol up to a concentration of 25 microg/g. Salsolinol is a dopaminergic active compound which binds to the D(2) receptor family, especially to the D(3) receptor with a K(i) of 0.48+/-0.021 micromol/l. It inhibits the formation of cyclic AMP and the release of beta-endorphin and ACTH in a pituitary cell system. Taking the detected concentration and the pharmacological properties into account, salsolinol seems to be one of the main psychoactive compounds present in cocoa and chocolate and might be included in chocolate addiction.
    背景与目标: :可可和巧克力中所含四氢异喹啉生物碱salsolinol的浓度最高为25 microg / g。 Salsolinol是一种多巴胺能活性化合物,可与D(2)受体家族,特别是K(i)为0.48 /-0.021 micromol / l的D(3)受体结合。它抑制垂体细胞系统中环状AMP的形成以及β-内啡肽和ACTH的释放。考虑到所检测到的浓度和药理特性,沙索萘醇似乎是可可和巧克力中存在的主要精神活性化合物之一,并且可能包括在巧克力成瘾中。

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